reidite

{{Short description|Polymorph of ZrSiO4}}

{{Infobox mineral

| name = Reidite

| category = Zircon group

| boxwidth =

| boxbgcolor = #7da7d9

| image =

| caption =

| formula = ZrSiO₄

| IMAsymbol = Rei{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3 |pages=291–320|doi=10.1180/mgm.2021.43 |bibcode=2021MinM...85..291W |s2cid=235729616 |doi-access=free}}

| molweight = 183.31 g/mol

| strunz = 9.AD.45

| dana =

| system = Tetragonal

| class = Dipyramidal (4/m)
H-M symbol: (4/m)

| symmetry = I4₁/a

| unit cell = a = 4.738, c = 10.506 [Å], Z = 4

| color = Colorless to white

| habit = Epitaxial - crystallographic alignment with a precursor mineral,

occurs as inclusions in other minerals.

| twinning =

| cleavage = None

| fracture = Irregular/uneven

| tenacity = Brittle

| mohs = 7.5

| luster = Adamantine

| refractive = n_ω=1.64, n_ε=1.655

| opticalprop = Uniaxial (+)

| birefringence = 0.0150

| pleochroism = None

| streak = White

| gravity = 5.16

| density =

| melt =

| fusibility =

| diagnostic =

| solubility =

| diaphaneity = Translucent

| other =

| references = {{cite web|title=Reidite|url=http://www.mindat.org/min-11467.html|website=mindat.org|publisher=Hudson Institute of Mineralogy|accessdate=18 March 2015}}{{cite web|title=Reidite Mineral Data|url=http://webmineral.com/data/Reidite.shtml#.VQivio7F-So|website=Webmineral.com|accessdate=18 March 2015}}}}

Reidite is a rare polymorph of ZrSiO₄ created when zircon experiences high pressure and temperature. Reidite is denser than zircon and has the same crystal structure as scheelite. All natural occurrences of reidite are associated with meteorite impact events.

On Earth, reidite has been reported from ten impact structures: the Chesapeake Bay Crater in Virginia; Ries Crater in Germany; Xiuyan Crater in China; Woodleigh Crater in Western Australia;[https://www.abc.net.au/news/2018-10-16/rare-mineral-reidite-found-in-woodleigh-meteorite-crater-in-wa/10382888 Discovery of reidite, one of the rarest minerals on Earth, may reveal Australia's biggest crater] ABC News, 16 October 2018. Retrieved 17 October 2018. Rock Elm Crater in Wisconsin;{{cite web| last1=Oskin| first1=Becky| title=Rare Mineral Discovered in Ancient Meteorite Impact Crater| url=http://www.livescience.com/48584-reidite-discovered-rock-elm-wisconsin.html| website=Livescience.com| date=3 November 2014|publisher=Livescience|accessdate=24 March 2015}} Dhala Crater in India;{{Cite journal|last1=Li|first1=Shan-Shan|last2=Keerthy|first2=S.|last3=Santosh|first3=M.|last4=Singh|first4=S.P.|last5=Deering|first5=C.D.|last6=Satyanarayanan|first6=M.|last7=Praveen|first7=M.N.|last8=Aneeshkumar|first8=V.|last9=Indu|first9=G.K.|title=Anatomy of impactites and shocked zircon grains from Dhala reveals Paleoproterozoic meteorite impact in the Archean basement rocks of Central India|journal=Gondwana Research|volume=54|pages=81–101 |date=February 2018 |doi=10.1016/j.gr.2017.10.006|bibcode=2018GondR..54...81L}} Stac Fada in Scotland; Haughton in Canada; Steen River in Canada, and Rochechouart in France. Reidite has also been found in one lunar meteorite.{{Cite journal |last1=Xing |first1=Weifan |last2=Lin |first2=Yangting |last3=Zhang |first3=Chi |last4=Zhang |first4=Mingming |last5=Hu |first5=Sen |last6=Hofmann |first6=Beda A. |last7=Sekine |first7=Toshimori |last8=Xiao |first8=Long |last9=Gu |first9=Lixin |date=2020-11-16 |title=Discovery of Reidite in the Lunar Meteorite Sayh al Uhaymir 169 |url=https://onlinelibrary.wiley.com/doi/10.1029/2020GL089583 |journal=Geophysical Research Letters |language=en |volume=47 |issue=21 |doi=10.1029/2020GL089583 |bibcode=2020GeoRL..4789583X |s2cid=226337486 |issn=0094-8276}}